Are some people invisible?

[Answered on Quora.com by Bill Otto]

Not in a literal sense.

But it has often been said that middle-aged women are perfect spies because they are invisible. No one notices them.

I was once invisible. I was a very young loan counselor at a credit union. Some people had trouble seeing me because they were expecting something else.

People who work as extras in Hollywood try to be invisible. They manage to keep you from seeing their faces, or any other personally identifiable features.

The more you look like you belong in the environment and behave exactly as expected, the more likely you are to be “invisible”.